This invention relates, in general, to semiconductor device, and more particularly to bipolar transistors and junction field effect transistors.
Semiconductor devices such as bipolar devices are becoming increasingly important in high frequency applications. Traditionally, the collector region of the bipolar device is formed using an epitaxial layer in conjunction with a buried layer. The formation of a buried layer solely for the formation of a collector region contributes significantly to the manufacturing cost of the device.
In addition, conventional bipolar devices have an appreciable base-collector capacitance, which reduces the maximum frequency response of the device. As is readily apparent, structures and methods are needed that overcome at least the above problems found in the prior art. It would be advantageous to manufacture such structures in a cost effective and reproducible manner.